Do not set input focus for combo boxes when SA focus moves to them

This was done back in
https://chromium-review.googlesource.com/c/chromium/src/+/2231660

likely to support sending arrow keys in a prior iteration to support combo
boxes.

R=dmazzoni@chromium.org

Fixed: 1137612
Change-Id: Iaa974ae8eecafc16612df092a5ebba36031a7d1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2472529
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817217}

chrome/browser/resources/chromeos/accessibility/switch_access/nodes/combo_box_node.js

@@ -36,7 +36,6 @@ class ComboBoxNode extends BasicNode {
     this.expandedChangedHandler_ = new RepeatedEventHandler(
         this.automationNode, chrome.automation.EventType.EXPANDED,
         () => this.onExpandedChanged(), {exactMatch: true});
-    this.automationNode.focus();
   }
 
   /** @override */